1. Field of the Invention
The present invention relates to a stage apparatus and, in particular, to a stage apparatus movable in XY directions.
2. Related Background Art
Conventionally, a stage apparatus is used, for example, in a microscope. The stage includes a base plate fixed on the microscope, an intermediate plate movable in the Y direction (in the back and forth directions relative to the microscope) relative to the base plate, and an upper plate on which a specimen is to be placed movable in the X direction perpendicular to the Y axis (in the right and left directions relative to the microscope). The upper plate is provided so that it is movable not only in the X direction but also in the Y direction integrally with the intermediate plate.
The intermediate plate is provided with a single-axis handle, and the stage can be independently moved in the X and Y directions.
A stage apparatus in which an operation handle for moving a stage in the X and Y directions is disposed on a base plate is also known(gee Japanese Unexamined Patent Publication Hei 9-127427).
In this stage, an intermediate plate (a plate moving in the Y direction) is moved by a rack and pinion, and an upper plate (a plate moving in the X direction) is moved in the Y direction integrally with the intermediate plate. A drive mechanism disposed between the operation handle and the upper plate for moving the upper plate includes two levers and a joining point and can follow the movement in the Y direction of the upper plate.
However, in the former case, when an observer moves the upper plate on which a specimen is placed in the Y direction, the observer has to move his or her hand with the single-axis handle because the single-axis handle also moves in the Y direction.
Meanwhile, an observer usually moves the stage while observing (observing through an eyepiece lens).
Accordingly, once the observer moves his or her hand off the handle, the observer has to grope for the handle, and when the handle is not stationary as described above, it is difficult to find the handle, and the operability of the stage is poor. In particular, when a wafer, a reticle, a liquid crystal substrate, etc. are to be observed, the stage should be large-sized, and thus the handle moves a longer distance and is more difficult to find.
Thus, the operability of the conventional stage apparatus used in a microscope is extremely poor, and, for an observer who uses the microscope for many hours, the operation of the stage has been very fatiguing work.
In the latter case, because the handle is stationary, the stage is easy to handle; however, the stage is structurally complicated, is hard to be manufactured with a high degree of precision (for example, to decrease backlash) and requires a large space to be incorporated.